One-Pot Synthesis of β-Hydroxy andβ-Malonate Esters from Enals

Significance

A one-pot synthesis of β-hydroxy and β-malonate esters from α,β-unsaturated aldehydes has been described. The authors have combined the amine-catalyzed epoxidation and cyclopropanation of enals with the carbene catalyzed ring-opening of 2-epoxy and 2-cyclopropyl aldehydes for the one-pot synthesis of β-functionalized esters. The best catalyst system was the combination of catalysts 1 and 2. With 10-20 mol% of catalyst 1 and 20-40 mol% of catalyst 2 excellent enantioselectivities (er = 95:5 to 98:2) have been obtained for different enals.